Study: Mass. women more apt to end Down syndrome pregnancies

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This chart depicts the estimated number of fetuses with Down syndrome at 10 weeks gestational age in Massachusetts from 1974-2010, with estimated outcomes of live births (black), elective terminations (gray) and losses to miscarriage (light gray). Source: Massachusetts General Hospital

This chart depicts the estimated number of fetuses with Down syndrome at 10 weeks gestational age in Massachusetts from 1974-2010, with estimated outcomes of live births (black), elective terminations (gray) and losses to miscarriage (light gray). Source: Massachusetts General Hospital

Bay State women are much more likely to decide to end Down syndrome pregnancies than women nationwide, according to a new study that shows ?49 percent of fetuses with the genetic condition that could have been carried to full-term were aborted statewide in 2010, compared to the national rate of ?30 percent.

And the numbers are only expected to increase with advances in prenatal screening for birth defects, researchers say.

“Down syndrome is a canary in a coal mine in a lot of ways,” said Dr. Brian Skotko of MassGeneral Hospital for Children and senior author of the study. “It’s reflective of how we practice medicine with these tests and how it’s changing.”

The paper, published in the journal Genetics in Medicine on Thursday, shows a national trend that seems to be magnified in Massachusetts, due in part to the widespread access to health care and medical technologies, authors say. The study found higher numbers of abortions in the Northeast and Hawaii and the lowest number in the South.

Prenatal screening has been around since the early 1970s, when only 2 percent of women — mostly those past prime child-bearing years — received amniocentesis, which extracts amniotic fluid with a needle through the belly. But over the last 15 years, less invasive screening methods that test the mother’s blood ?for abnormalities have become more common.

“We know through the data that, as the number of the elective terminations expands, it’s reflective of the advancements in prenatal technology,” ?Skotko said.

“It’s a simple numbers game.”

Because there’s a five-year lag in available data, Skotko said, the numbers don’t include the increase that has likely occurred since 2011, when an even more sophisticated blood test that examines the fetus’ DNA came onto the screening scene.

“I think the world of genetics is exploding throughout medicine in so many different ways,” said Brigham and Women’s Hospital geneticist Dr. Robert Green, who was not involved in the study. “Almost nowhere has the advancement been quite as dramatic in such a short ?time as it has been in prenatal screening.”

But the high numbers of abortions also show a potential misconception of what it means to raise a child with Down syndrome, which has changed significantly in recent years, said Catherine Bearce Nowak, clinical director of the Feingold Center for Children, which works with children who have ?genetic conditions.

Although there are challenges — about 40 percent of children born with Down syndrome have heart defects — early intervention programs and educational opportunities have expanded over the last decade.

“I do think there’s still a dated perception only because people have a limited exposure or limited opportunity to interact with people with Down syndrome,” Nowak said. “With the right mix of therapies, we can pull out the best potential for these children.”